# Analgesics in Dentistry

> Analgesics for BDS Pharmacology — paracetamol, NSAIDs and opioids for dental pain, key doses, combinations, contraindications and the WHO analgesic ladder.

- Canonical URL: https://prepelephant.com/topics/bds/pharmacology/analgesics-dental-pharm-ss
- Exam / course: BDS · Subject: Pharmacology
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-02
- Last updated: 2026-10-02
- How to cite: "Analgesics in Dentistry", PrepElephant, https://prepelephant.com/topics/bds/pharmacology/analgesics-dental-pharm-ss

## Direct answer

For pain after a dental extraction, a combination of ibuprofen and paracetamol relieves pain better than either drug alone and better than most opioids — that single evidence-based sentence drives most dental analgesic prescribing. Paracetamol 1 g up to four times a day (maximum 4 g) is the safe baseline in pregnancy, asthma and ulcer disease; ibuprofen 400 mg every 6–8 hours adds anti-inflammatory power when the stomach, kidneys and trimester permit. Opioids such as tramadol and codeine are add-ons for specific situations, never first-line for inflammatory dental pain.

## What you must remember

- Paracetamol: 1 g every 6 hours, maximum 4 g in 24 hours (2–3 g in liver disease or regular alcohol use); central action, negligible anti-inflammatory effect, N-acetylcysteine the specific antidote in overdose.
- Ibuprofen: 400 mg every 6–8 hours, up to 1.2 g/day over the counter and 2.4 g/day on prescription; the best tolerated NSAID and first choice for post-extraction pain.
- Aspirin is avoided under 16 years with viral illness — Reye's syndrome; it irreversibly acetylates COX, hence its antiplatelet role at 75–150 mg.
- NSAID contraindications: peptic ulcer, significant renal impairment, third trimester of pregnancy (premature ductus arteriosus closure), and aspirin-sensitive asthma — the Samter triad of asthma, nasal polyps and NSAID reaction.
- Etoricoxib 90 mg once daily is the selective COX-2 option when there is ulcer history, with cardiovascular caution.
- Tramadol 50–100 mg up to 400 mg/day (300 mg in the elderly) carries seizure risk with SSRIs; codeine is a CYP2D6 prodrug, unreliable in poor metabolisers and contraindicated in children and breastfeeding mothers.
- Pre-emptive analgesia: an analgesic taken before surgery reduces postoperative requirements; dosing before the local anaesthetic wears off prevents the pain spike.

## Matching the drug to the patient in the chair

Build the prescription around three questions: how inflammatory is the pain, what does the patient tolerate, and how old are they? A healthy adult after third molar surgery gets ibuprofen 400 mg with paracetamol 500–1000 mg, started before the local anaesthetic regresses. Change one variable at a time. A duodenal ulcer history drops the ibuprofen: paracetamol 1 g four times a day, with etoricoxib 90 mg only if a physician agrees and a proton pump inhibitor is running. Asthma with a previous NSAID reaction removes the entire NSAID class — paracetamol alone, with tramadol 50 mg short-term if pain breaks through. A 78-year-old with stage 3 kidney disease cannot take NSAIDs and needs tramadol dose reduction, so paracetamol 1 g four times a day becomes the ceiling. A 20 kg five-year-old converts to weight-based dosing: paracetamol 15 mg/kg (300 mg) every 6 hours, or ibuprofen 5–10 mg/kg every 8 hours. Notice that the sequence never starts with an opioid — dental pain is prostaglandin-mediated inflammation, which is precisely what NSAIDs switch off and opioids merely mask.

## How the exam frames it

Analgesics are tested as one-liners with named numbers: the Reye's syndrome question (aspirin), the overdose antidote (N-acetylcysteine), the maximum daily doses (4 g paracetamol, 2.4 g prescription ibuprofen), the Samter triad, and the safest analgesic in pregnancy (paracetamol). The subtler trap is mechanism language: aspirin is the irreversible COX inhibitor while ibuprofen is reversible and competitive — and ibuprofen taken just before low-dose aspirin can block aspirin's antiplatelet access to the enzyme. When a viva asks why NSAIDs beat opioids for dental pain, answer with the pharmacology: the pain source is inflammatory and prostaglandin-driven, so removing the mediator outperforms blunting the perception.

## Frequently asked questions

### Why do NSAIDs relieve dental pain better than opioids?

Post-extraction and pulpal pain is inflammatory and prostaglandin-driven; NSAIDs remove the mediator, while opioids only damp central perception and add sedation and constipation.

### What is the maximum daily dose of paracetamol?

4 g in 24 hours for a healthy adult, reduced to about 2–3 g in chronic liver disease, regular alcohol use, malnutrition or the frail elderly.

### Which analgesic is contraindicated in a child with chickenpox?

Aspirin — its association with Reye's syndrome confines paediatric use to specific rheumatological indications under specialist care.

### What is the antidote for paracetamol poisoning?

Intravenous N-acetylcysteine, which replenishes glutathione and detoxifies the reactive metabolite; it works best within 8–10 hours of ingestion.

### Which analgesic suits a patient with peptic ulcer disease?

Paracetamol first; if an anti-inflammatory is essential, a selective COX-2 inhibitor such as etoricoxib with proton pump cover, weighing the cardiovascular risk.

### Why is codeine unsuitable in breastfeeding?

A CYP2D6 ultrarapid metaboliser converts codeine to excess morphine, which reaches the infant through milk and has caused fatal respiratory depression — regulators contraindicate the pair.